Piping On Fondant

I'm making a cake for my cousin's first birthay. It's the perfect time to practice my piping as I am VERY new at it. I made frosting that must be refrigerated as it has 1/3 cup of milk in it. Can I pipe on fondant and then refrigerate it? Will it bleed tomorrow when I remove it from the refrigerator? I was also thinking about maybe piping with candy melts ... ??Thanks for your tips in advance!Amy

What recipe did you use for the icing? Just because there's milk in it doesn't necessarily mean it has to be refrigerated; most American buttercreams have enough sugar to preserve the dairy and render them stable at room temp.

I unfortunately don't have time for testing ... it needs to be ready by noon tomorrow. i've decided to pipe (more like paint with a paintbrush) the cherry blossom branches with candy melts and probably just print the "Happy Birthday" on frosting sheets ... just to be on the safe side. I'll be testing it however for future reference.